1. Technical Field
The present invention relates to an inflatable vehicle occupant restraint, and is particularly directed to an air bag made from one or more panels of fabric material sewn in a manner to minimize the volume of the air bag when in a folded condition.
2. Description of the Prior Art
A typical air bag module includes an air bag made from one or more panels of fabric material sewn to define an inflation fluid volume. In the process of sewing the air bag, stitching lines are used to join layers of material at seams. After the air bag is sewn, it is folded to fit into a housing along with an inflator to form the module. The module is mounted in a vehicle. In the event of a vehicle collision, the inflator is actuated to direct inflation fluid into the air bag. The air bag inflates from the folded and stored condition to an unfolded and inflated condition to restrain the vehicle occupant.
An air bag module which is used to restrain a front seat passenger of a vehicle is disposed in the vehicle instrument panel. The space available for an air bag module is limited in this location. Thus, it is desirable to minimize the space occupied by the folded air bag as part of the air bag module.
The stitching lines of an air bag increase the thickness of the air bag when folded. Thus, the air bag is generally thicker at locations where a stitching line is present than at locations where there is no stitching line. The thickness of a folded air bag is undesirably increased where a series of stitching lines are disposed in overlying relationship with each other.